the present invention relates to a disposable cassette for detecting nucleic acids or performing other assays. the cassette can be inserted into a base station during use. the cassette has several features to ensure correct operation of the device under gravity, such as ventilation pockets to allow sample fluid to flow from one chamber to the next when the ventilation bag is unsealed. ventilation pockets have protrusions to help prevent accidental leakage. the cassette may also have a gasket to ensure free air movement between open ventilation pockets. a flexible circuit with standardized metallic electrical components arranged in a thermostable material can be in direct contact with the fluid in the chambers and has resistant heating elements aligned with the ventilation bags and chambers. recesses in channels or cassette chambers may have structures, such as ribs or grooves to direct the flow of fluid to increase rehydration of lyophilized reagents disposed in the recess. flow diverters in the chambers can slow the sample fluid flow rate and increase the effective length of the fluid flow path, allowing more precise control of the fluid flow in the cassette. the top of each chamber can have a projection that prevents the flow of capillary fluid through the top of the chamber, reducing or preventing the sequestering of resuspended reagent from the mass of the reaction solution volume.a presente invenção refere-se a um cassete descartável para detectar ácidos nucleicos ou realizar outros ensaios. o cassete pode ser inserido em uma estação de base durante o uso. o cassete possui vários recursos para garantir a operação correta do dispositivo sob gravidade, como bolsas de ventilação para permitir o fluxo de fluido de amostra de uma câmara para a próxima quando a bolsa de ventilação estiver sem vedação. as bolsas de ventilação têm protuberâncias para ajudar a evitar a revedação acidental. o cassete também pode ter uma junta para garantir movimento de ar livre entre bol